Press fixture



A. LEFERE PRESS FIXTURE March 16, 1943.

Filed April 1, 1940 2 sheets-sheet 2 ALIUDR LEP by a. hollow conical die.

' operative: position,

Patented Mar. 16, 1943 UNITED STATES PATENT OFFICE.

Alidor Lefere, Jackson, Mich., assignor to Lefere Forge & Machine Company, Jackson, Mich, a

corporation of Michigan Application April 1, 1940, Serial No. 327,114

11 Claims.

from slugs by pressing. In. forming such blanks on; a press, a slug is forced over a conical plug However, considerable difficulty is. encountered in supporting the slugs in centered relation with respect to the plug immediately prior to. engagement. with the slugs bythe hollow die, According to the. present invention, slugs: are quickly and readily centered by pivoted fingers, projecting radially in toward the slug into engagementftherewith, the fingers. being pivotable out of centering relation with the slugs by the hollow die as it moves downwardly intoengagement therewith. "Means are provided for automatically holding the. fingers in inoperative positi'on in order to permit the removal oi'ithe finished blank. i

An object of the invention is to provide a centering fixture for presses.

Another object of the invention is to provide pivoted {fingers'for' centering work about to be operated upon by a press. I

Still another object of'the invention is to provide centering means for centering work about to be operated upon by a press, the centering means being movable from operative position during the operation of the press andbeing automatically retained in inoperative position for permitting removal of work.

. Still: another object of the invention is toprovide a'centering fixture for pressescomprising centering fingers arranged to beautomatically removed from operative position and manually returned to operative position.

Theseand otherobj'ects will be apparent from the following specification when taken with'the accompanying drawings in. which:-

Fig. 1 is. a vertical section of a press disclosing the fixture according. to the present invention'i'n Fig; 2. is a section on the line II-eII of Fig. 1, Fig. 3. is a section on the. line III-III Fig. 1, Fig. i is a, view taken in the directionof the arrows IV-i-IV of Fig.1,- 1

Fig. is a plan View of the structure disclosed inFig. 4., and i i j. I

, Fig. 6 is an elevatioi of the centering finger con-trolling cylinder.

Referring particularly to the drawings, the reference. character I indicatesv a press of conventional construction, including a bed 2, and ways 3 for guiding-a ram Suitably secured to the ram 4 is a holder 5 supporting a conical upper die part ti for cooperating with a tapered lower die part or plug 1. p

As shown, a slug or work piece 8 is resting on the top of the plug 1 and has just been engaged by the downwardly moving die 6 under the action of the ram 4'. Heretofore, at this" stage of; the operation of pressing the slug 8 over the-plug 1 by the die 6, considerable difiiculty has been encountered in maintaining the slug 8 in centered relation to the plug, 1. This difiiculty has been eliminated by the present invention by providing centering fingers 9 as. shown particularly in Figs. 1 and 4. Thefingers 9 are pivoted in vertical slots IO, in a centering support H. The'centering support H, as shown inthe drawings, is cylindrical in form andis secured to a base It by screws H3. The base i2 has secured toit the plug 1 by means of a screw it and is secured by screws IE to a conventional stool l5 having'legs l1 supporting it from the bed 2. The fingers 9 are securedto the centering member H by means of pins 20,. disclosed particularly in Figs. 1*, 4 and and 5.

Threaded to the outside surface of the centering'member H is a ring 21 serving; as an abutment to limit the pivotal movement of the fingersfi under the action. of springs 22, secured to the; outer ends of the fingers 9-at one end and-to the pins 23 in the base I2 at the other end. rAs willbe clear from Fig. 1,' the position of the ring 2.1-: may be adjusted up and down the outside surface of the centering member H- to adjust the position to. which the fingers 9: are; pivoted under the action of the springs22.

The fingers 9 project radially inwardly into engagement with the slug 8 to center the same on the plug-l. Each of the fingers 9. is provided with aslug'enga'ging surface 24 whereby a slug resting on the top of the plug 1' is maintained ina fixed predetermined relation thereto pending the initial downward movement of the die 6; For major changesin the size of the slugs and openings 28 in the centering member H are for the purpose of conducting away scale and dirt which falls into the enclosures defined by the cylinder and the centering member H respectively.

The upper end of the cylinder 25 is necked inwardly, as shown in Figs, 1 and 6, and is provided with a slot 29 for each finger 9 and in each of which during predetermined portions of each cycle of operation, the outer end of one finger 9 projects. The slots 29 are each defined by one straight edge and a curved camming edge 3|.

Projecting radially from the cylinder 25 is a handle 32 in the form of a rod, threaded into a boss 33, shown particularly in Fig. 2. Cooperataction of the springs 22.

ing with the handle 32 is a sword member 34,

secured by screws to the ram 4 and provided with an inclined camming surface 36.

The plug 1 has associated with it a conventional stripper 49 for stripping work from the plug 1 after it has been formed thereover by the upper die part 6. The stripper may be actuated in any conventional manner, but as shown, is connected by depending rods 4|, projecting through the top surface of the stool l5 to a laterally extending bar 42. The bar 42 at opposite ends is provided with openings 43, through which project rods 44, connected respectively to opposite sides of the ram 4. Disposed on the rods 44 are nuts 45 and 46 on opposite sides of the openings 43, whereby as the rods 44 move up and down with the ram 4, a lost motion connection with the bar 42 is provided. The connection is such that the nuts 46 engage with the bottom of the bar 42 just prior to the ram 4 reaching its upper position to move the stripper to the dotted position disclosed in Fig. 1. In the form of the stripper operating mechanism disclosed, openings 41 are provided in the press bed 2 through which the rods 44 and their nuts 46 project.

In operation of the structure according to the present invention, the fingers 9 of the correct size having been pivoted to the centering member l l, a slug or work piece 8 is disposed on the top of the plug 7 and is maintained there in centered relation by the fingers 9. The press is then actuated to move the top die part 6 downwardly into engagement with the slug 8 to force the same over the plug 1 to form a conical blank. The parts should be so proportioned that at substantially the same time that the upper 'die part 6 comes into engagement with the slug 8, the lower face of the upper die part 6 and its holder 5 come into engagement with the tops of the fingers 9, and pivot them about the pins 20 away from the slug 8 and into inoperativeposition. It will be observed that since there is a very small distance between the'pins 20 and the portions of the die holder 5 which engage the fingers 9, only a slight downward movement of the die holder 5 and the upper die part 6 will be necessary to provide a substantial pivotal movement of the fingers 9. In this way, as the metal of the slug 8 starts to spread over theplug 1, the fingers 9 will have pivoted sufficiently to prevent them from being engaged by the expanding metal of the slug 8.

In view of the fact that the fingers 9 are pivoted about the pins 20 by the springs 22', it will appear that other things being equal, upon retraction of the upper die part Band the holder 5 therefore, the fingers 9 would resume their position disclosed in Fig. 1. This would result in top of the cylinder 25, adjacent each slot 29, will be opposite a finger 9 and prevent its returning to the position shown in Fig. 1 under the After the blank has been removed from the press, the fingers 9 may .be returned to the position shown in Fig. 1 by rotating the cylinder 25, in the opposite direction to that which it was moved by the sword member 34, through manual force applied to the handle 32. As the cylinder 25 is rotated, the fingers 91 being urged against the top flat edges 48 of the cylinder 25, will each slide therealong until they reach a slot 29 at which point they will drop over a curved edge 3| and into the bottom of a slot 29. The vertical edges 30 abutting against the fingers 9 serve as stops to limit the return rotation of the cylinder 25. For the purpose of making possible movement of the fingers 9 independently of the action of the upper die part6 and its holder 5,'the curved surfaces 3| of the slots 29 serve as cams so that when the handle 32 is actuated to rotate the cylinder 25 in the direction it would be rotated by the camming surface 36 of the sword mem ber 34, the surfaces 3| will engage with the respective fingers 9 to rotate them into inoperative position. It will be understood that when the fingers 9 are rotated under the action of the upper die part 6 and its holder 5, and the cylinder 25 is rotated under the action of the camming surface 36 of the sword member 34, the camming edges 31 are inoperative.

It is to be understood that in the foregoing" description,the specific form of the die members 1 and 8 are not essential to the invention, although the specific form of die members shown, which are for forming blanks for artillery projectiles, are particularly adapted tohave employed therewith the centering means disclosed. Furthermore, it is to be understood that the press and stripper and the operating mechanism for the stripper are shown diagrammatically and only for the purpose of illustrating the invention. In the claims, the terms top and bottomas applied to the die parts are to be considered as designating the relation of th die parts to each other rather than as constitutinga strict limitation as to position.

Having thus described my invention, what I de sire to secure by Letters Patent and claim is: h

1. The combination with a two part die including a male part and 'a female part for movement over said male part, of. a centering frame, centering fingers pivoted to said frame and pro-' jectableradially toward the longitudinal axis of said male part for maintaining a' slug in centered relation-on the outer end of said male part, and means movable with said female part operative'to maintain said fingers in inoperativeposition after the retraction of said female part and said means movable therewith.

2. The combination with a two part die including a bottom part and a top part, of a frame circumscribing said bottom part, means pivoted in a vertical plane and supported by said frame for maintaining a'work piece in a predetermined relation to said bottom part, yieldable means for pivoting said maintaining means into operative position, means to limit the pivotal movement of said maintaining means under the action of said yieldable means and thus to determine the operative position of said maintaining means, and means movable with said top part engageable withsaid maintaining means to move the same to inoperative position.

3. The combination with a two part die including a bottom part and a top part, of a circumscribing frame about said bottom part, fingers pivoted to said frame and circumferentially spaced thereabout, said fingers extending inwardly toward the longitudinal axis of said bottom part for maintaining a work piece in a predetermined relation to said bottom part, and means movable with said top part engageable with said fingers to pivot them into inoperative position.

4. The combination with a two part die including a bottom part and a top part, of a frame, fingers pivoted to said frame, said fingers extending inwardly toward the longitudinal axis of said bottom part for maintaining a work piece in a predetermined relation to said bottom part, means operative to move said fingers to inoperative position during downward movement of said top part, and means movable with said top part operative to maintain said fingers out of operative position after retraction of said top part and said means movable therewith.

5. The combination with a two part die including a bottom part and a top part, of a frame, fingers pivoted to said frame, said fingers extending inwardly toward the longitudinal axis of said bottom part for maintaining a work piece in a predetermined relation to said bottom part, means engageable with said fingers to move the same into inoperative position during downward movement of said top part, means engageable with said fingers for maintaining the same out of operative relation following the retraction of said top part and means movable therewith, and means operative upon downward movement of said top part to move said last named engaging means into said engaging relation with said fingers.

6. The combination with a top die part movable with a press ram and a bottom die part supported from a press bed, of means for maintaining a work piece in a predetermined relation to said bottom die part, means movable with said top die part engageable with said maintaining means to move the same into inoperative position, movable means to hold said maintaining means in inoperative position following retraction of said top die part, and a cam depending from said ram for actuating said last named means upon downward movement of said ram to move said last named means into operative position.

7. The combination with a top die part movable with a press ram and a bottom die part supported from a press bed, of fingers for maintaining a work piece in a predetermined relation to said bottom die part, means for pivotally supporting said fingers, means for moving said fingers into inoperative position during downward movement of said top die part, a finger engaging member supported with respect to said bottom die part and having portions for holding said fingers in inoperative position, said finger engaging member having a plurality of slots in each one of which one end of one of said fingers is disposedwhile it is in work piece maintaining position, and a cam movable downwardly with said ram for actuating said finger engaging member for moving said slots out of register with said fingers upon downward movement of said ram whereby said member supports said fingers in inoperative position following retraction of said top die part.

8. A fixture of the character described comprising a base, a centering support carried by said base, a plurality of work piece centering fingers pivoted to said centering support, a cylinder supported on said base surrounding said centering support, said cylinder having a plurality of slots in each one of which a portion of one of said centering fingers is disposed while in work piece centering position, and means for rotating said cylinder on said base with respect to said centering member for moving said slots out of re ister with said fingers under predetermined conditions whereby said cylinder maintains said fingers in inoperative position under predetermined conditions.

9. The combination with a top die part movable with a press ram and a bottom die part supported from a press bed, of a frame, means supported by said frame for maintaining a work piece in a predetermined relation to said bottom die part, means supported by said frame for adjusting said maintaining means for different sized work pieces, means movable with said top die part engageable with said maintaining means to move the same into inoperative position, movable means to hold said maintaining means in inoperative position following retraction of said top die part, and a cam depending from said ram for actuating said movable means upon downward movement of said ram to move said movable means into position to hold said maintaining means in inoperative position.

10. The combination with a two part die including a bottom part and a top part, of a frame circumscribing said bottom part, means pivoted in a vertical plane and supported by said frame for maintaining a work piece in a predetermined relation to said bottom part, yieldable means for pivoting said maintaining means into operative position, adjustable means to limit the pivotal movement of said maintaining means under the action of said yieldable means and thus to determine the operative position of said maintaining means, and means movable with said top part engageable with said maintaining means to move the same to inoperative position.

11. The combination with a two part die including a bottom part and a top part, of a circumscribing frame about said bottom part, fingers pivoted to said frame and circumferentially spaced thereabout, said fingers extending inwardly toward the longitudinal axis of said bottom part for maintaining a work piece in a predetermined relation to said bottom part, and means movable with said top part to pivot said fingers into inoperative position.

ALIDOR LEFERE. 

